swarming: display named caches in task UI

appengine/swarming/ui/res/imp/taskpage/task-page.html

 <!--
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 
   This in an HTML Import-able file that contains the definition
   of the following elements:
 
     <task-page>
 
@@ skipping 314 matching lines @@
                   <tr>
                     <td>[[cipd.path]]/</td>
                   </tr>
                   <tr>
                     <td><b>Requested:</b>[[cipd.requested]]</td>
                   </tr>
                   <tr hidden$="[[_wasNotPickedUp(_result)]]">
                     <td><b>Actual:</b>[[cipd.actual]]</td>
                   </tr>
                 </template>
+
+                <tr hidden$="[[_empty(_request.properties.caches)]]">
+                  <td rowspan$="[[_rowspan(_request.properties.caches)]]">Named caches</td>
+                </tr>
+                <template is="dom-repeat" items="[[_request.properties.caches]]" as="cache">
+                  <tr>
+                    <td><span>[[cache.name]]</span>:<span>[[cache.path]]</span></td>
+                  </tr>
+                </template>
+
               </template>
             </table>
 
             <div class="title">Task Execution</div>
             <template is="dom-if" if="[[_wasPickedUp(_result)]]">
               <table>
                 <tr>
                   <td>Bot assigned to task</td>
                   <td><a href$="[[_botLink(_result.bot_id)]]">[[_result.bot_id]]</td>
                 </tr>
@@ skipping 350 matching lines @@
             console.log("Task could not be retried", e);
           }
         );
       },
 
       _rowspan: function(dims) {
         dims = dims || [];
         return dims.length + 1;
       },
 
+      _empty: function(array) {
+        return array.length == 0;
+      },
+
       _supportsMilo: function(request, showRaw) {
         return !showRaw && request && this._tag(request, "allow_milo");
       },
 
       _state: function(result) {
         if (!result) {
           return "";
         }
         if (result.state === this.COMPLETED) {
           if (result.failure) {
@@ skipping 26 matching lines @@
         return result && result.state !== this.PENDING && result.state !== this.CANCELED && result.state != this.EXPIRED;
       },
 
       _wasNotPickedUp: function(result) {
         return result && !this._wasPickedUp(result);
       },
     });
   })();
   </script>
 </dom-module>